Polo 6n 2.3 V5 conversion

Discussion in 'Fox/Lupo/Polo' started by Callum1509, Apr 16, 2020.

  1. Callum1509 New Member

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    As the title goes I plan on doing a 2.3 v5 to a polo 6n 1.4 16v.

    What I’ve already got is a mk4 golf v5 for the parts.

    has anyone got any info on what’s needed and any info on the electrical side of the conversation? But any help or input would be really appreciated.
    I do have some experience doing conversions I’ve got a mk3.5 cabrio that I’ve converted to a vr6.
     
  2. rubjonny

    rubjonny Administrator Admin

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    I have plenty wiring diagrams in my signature link, start there.

    how late is the polo? the early ones have CE2 fusebox, later ones its similar to mk4 with fully integrated engine bay loom to a big multi plug. if you pull the bay loom out split out all the ecu specific stuff then drop the big ecu plug half on top, splice that in. add the t14a plug same as you would a mk1/2/3 swap, then main sensor loom will just plug in. if its later type with ecu relay I re-route the relay live to the battery instead saves a bit of faff truing to tap into a live inside the car
     
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  3. Callum1509 New Member

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    Thanks for the reply and the info the polo is a 1999 1.4 16v.

    I’ve just removed the engine and box from the polo and am now removing the engine and box from the golf then I’ll get the loom out of the golf hopefully today to.
     
  4. Toyotec

    Toyotec CGTI Committee - Happy helper at large Admin

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    Post pictures up of the loom you removed from the Polo.

    The VR5 is it a AGZ (M3.8.5) or a AQN (ME7.1)? I can cover you with what you need to know if it is a 20v V5.
     
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  5. Callum1509 New Member

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    The engine in the Golf is an AQN. I haven’t removed the loom from the polo yet though will post pick up when I have done.
     
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  6. Callum1509 New Member

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    Progress so far engine and gearbox removed from both cars. One half of the mk4 engine/ECU loom removed and currently removing the t14a part of the loom. Haven’t made much progress with the polo loom today, rains slowing things down. Anyone know if any factory engine mounts can be used or it’s all got to be custom.
     
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  7. Callum1509 New Member

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    Polo Bay
    [​IMG]

    mk4 big plug side of ECU loom
    [​IMG]

    Does this side of the ECU loom plug into the Polo fusebox or do i Need to cut the plugs off and cut the original Polo ECU plug off and splice the mk4 loom into the original Polo loom? as for the t14a plug where am i splicing this into the Polo? sorry for all the questions mk4 platform is completly new to me.
    [​IMG]
     
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  8. rubjonny

    rubjonny Administrator Admin

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    you'll have to splice the mk4 wiring into the polo wiring, they dont plug together.

    if the polo was later type with 120 pin plug you can de-pin all the fusebox side and insert into the MK4 ecu plug, I did that for one of the looms I had to do which cut down on the work required
     
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  9. Callum1509 New Member

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    In terms of splicing the mk4 loom into the polo loom is it a case of splice into the same colour wires or is there a guide of which wire splices into which?
     
  10. rubjonny

    rubjonny Administrator Admin

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    the wire colours wont always match and if its the later type Polo wiring there is no specific guide for it. if its an early one with CE2 fusebox you can use my 20v guide :)

    we can help you through it though, the first step is strip out all the old ECU wiring keeping hold of all the wires that run inside the car from the ECU. ID all of these wires, then we can use the 20v guides to figure out what needs splicing where. you'll want to extend the DBW pedal wiring blue plug so it can be moved inside the car, then mount the pedal.

    run the clutch and brake switch wires inside and wire them up to pedal switches, splice the t14a plug on the polo loom so your sensor harness can plug in. there are a couple multi pin plugs on the polo loom which have the dash sensor wires you want to re-direct to the t14a plus a couple power pins you'll need.

    as I say for main ecu relay power from T6/4 I ran that straight to the battery, if you have or can get a 15a fuse that'll fit inside the polo battery fusebox thats perfect, if not you can fit one inline. I add pins to the wires and use one of the empty pin holders inside the mk4 relay fusebox for this purpose. either that or extend the live feed inside the car and find a suitable permanent live to tap into.
     
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  11. Callum1509 New Member

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    Right plan for today then is to get the polo dash out and get stripping the loom back to the fuse box see how far I get with that today :thumbup:
     
  12. Tristan Forum Junkie

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    Great work.
     

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